There are lots of tools available on web for conversion of MBOX file to PST format. But I would like to suggest before using any paid tool you must try the manual technique for conversion. I also found aninformative article that clearly defined the manual steps for MBOX to PST conversion. Check this article here:- Convert MBOX mail into Outlook PST.

Best MBOX to PST Converter application whcih can smoothly transfer or move all emails and other MBOX files of Apple Mail to Outlook PST format within few clicks. It provides you with a stop solution for successful conversion of MBOX files into Apple Mail, Entourage, Thunderbird or Power mail in Outlook PST file created importable perform. See more: http://www.mboxtopstconverter.pcrecoverytools.com/